The present disclosure relates to a refrigerator.
In general, defrosted water formed by removing frost from an evaporator of a refrigerator is introduced into a machinery chamber through a drain member. In this case, a tube drain may be used to efficiently discharge the defrosted water. However, the tube drain may undesirably function as a passage through which hot air from the machinery chamber is introduced into the evaporator, which increases an inner load of the refrigerator and power consumption thereof.
To prevent such introduction of high temperature air into an evaporation chamber, a cap member may be installed on an outlet end of a drain tube.
FIG. 1 is a perspective view illustrating a drain pipe in the related art.
Referring to FIG. 1, a drain pipe 1 in the relate art includes: an inlet end 1a connected to a drain pan disposed under an evaporator; and an outlet end 1b installed on a machinery chamber. A drain cap 2 is installed on the outlet end 1b. 
Under this structure, hot air staying in the machinery chamber is prevented from being introduced into an evaporation chamber. However, it may be difficult to open a refrigerator door. This is because when the refrigerator door is opened, the inner space of a refrigerator is under negative pressure.